1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * uprobes-based tracing events 4 * 5 * Copyright (C) IBM Corporation, 2010-2012 6 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> 7 */ 8 #define pr_fmt(fmt) "trace_uprobe: " fmt 9 10 #include <linux/bpf-cgroup.h> 11 #include <linux/security.h> 12 #include <linux/ctype.h> 13 #include <linux/module.h> 14 #include <linux/uaccess.h> 15 #include <linux/uprobes.h> 16 #include <linux/namei.h> 17 #include <linux/string.h> 18 #include <linux/rculist.h> 19 #include <linux/filter.h> 20 21 #include "trace_dynevent.h" 22 #include "trace_probe.h" 23 #include "trace_probe_tmpl.h" 24 25 #define UPROBE_EVENT_SYSTEM "uprobes" 26 27 struct uprobe_trace_entry_head { 28 struct trace_entry ent; 29 unsigned long vaddr[]; 30 }; 31 32 #define SIZEOF_TRACE_ENTRY(is_return) \ 33 (sizeof(struct uprobe_trace_entry_head) + \ 34 sizeof(unsigned long) * (is_return ? 2 : 1)) 35 36 #define DATAOF_TRACE_ENTRY(entry, is_return) \ 37 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) 38 39 static int trace_uprobe_create(const char *raw_command); 40 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); 41 static int trace_uprobe_release(struct dyn_event *ev); 42 static bool trace_uprobe_is_busy(struct dyn_event *ev); 43 static bool trace_uprobe_match(const char *system, const char *event, 44 int argc, const char **argv, struct dyn_event *ev); 45 46 static struct dyn_event_operations trace_uprobe_ops = { 47 .create = trace_uprobe_create, 48 .show = trace_uprobe_show, 49 .is_busy = trace_uprobe_is_busy, 50 .free = trace_uprobe_release, 51 .match = trace_uprobe_match, 52 }; 53 54 /* 55 * uprobe event core functions 56 */ 57 struct trace_uprobe { 58 struct dyn_event devent; 59 struct uprobe_consumer consumer; 60 struct path path; 61 struct inode *inode; 62 char *filename; 63 unsigned long offset; 64 unsigned long ref_ctr_offset; 65 unsigned long nhit; 66 struct trace_probe tp; 67 }; 68 69 static bool is_trace_uprobe(struct dyn_event *ev) 70 { 71 return ev->ops == &trace_uprobe_ops; 72 } 73 74 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) 75 { 76 return container_of(ev, struct trace_uprobe, devent); 77 } 78 79 /** 80 * for_each_trace_uprobe - iterate over the trace_uprobe list 81 * @pos: the struct trace_uprobe * for each entry 82 * @dpos: the struct dyn_event * to use as a loop cursor 83 */ 84 #define for_each_trace_uprobe(pos, dpos) \ 85 for_each_dyn_event(dpos) \ 86 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) 87 88 static int register_uprobe_event(struct trace_uprobe *tu); 89 static int unregister_uprobe_event(struct trace_uprobe *tu); 90 91 struct uprobe_dispatch_data { 92 struct trace_uprobe *tu; 93 unsigned long bp_addr; 94 }; 95 96 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); 97 static int uretprobe_dispatcher(struct uprobe_consumer *con, 98 unsigned long func, struct pt_regs *regs); 99 100 #ifdef CONFIG_STACK_GROWSUP 101 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 102 { 103 return addr - (n * sizeof(long)); 104 } 105 #else 106 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 107 { 108 return addr + (n * sizeof(long)); 109 } 110 #endif 111 112 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) 113 { 114 unsigned long ret; 115 unsigned long addr = user_stack_pointer(regs); 116 117 addr = adjust_stack_addr(addr, n); 118 119 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) 120 return 0; 121 122 return ret; 123 } 124 125 /* 126 * Uprobes-specific fetch functions 127 */ 128 static nokprobe_inline int 129 probe_mem_read(void *dest, void *src, size_t size) 130 { 131 void __user *vaddr = (void __force __user *)src; 132 133 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; 134 } 135 136 static nokprobe_inline int 137 probe_mem_read_user(void *dest, void *src, size_t size) 138 { 139 return probe_mem_read(dest, src, size); 140 } 141 142 /* 143 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 144 * length and relative data location. 145 */ 146 static nokprobe_inline int 147 fetch_store_string(unsigned long addr, void *dest, void *base) 148 { 149 long ret; 150 u32 loc = *(u32 *)dest; 151 int maxlen = get_loc_len(loc); 152 u8 *dst = get_loc_data(dest, base); 153 void __user *src = (void __force __user *) addr; 154 155 if (unlikely(!maxlen)) 156 return -ENOMEM; 157 158 if (addr == FETCH_TOKEN_COMM) 159 ret = strlcpy(dst, current->comm, maxlen); 160 else 161 ret = strncpy_from_user(dst, src, maxlen); 162 if (ret >= 0) { 163 if (ret == maxlen) 164 dst[ret - 1] = '\0'; 165 else 166 /* 167 * Include the terminating null byte. In this case it 168 * was copied by strncpy_from_user but not accounted 169 * for in ret. 170 */ 171 ret++; 172 *(u32 *)dest = make_data_loc(ret, (void *)dst - base); 173 } 174 175 return ret; 176 } 177 178 static nokprobe_inline int 179 fetch_store_string_user(unsigned long addr, void *dest, void *base) 180 { 181 return fetch_store_string(addr, dest, base); 182 } 183 184 /* Return the length of string -- including null terminal byte */ 185 static nokprobe_inline int 186 fetch_store_strlen(unsigned long addr) 187 { 188 int len; 189 void __user *vaddr = (void __force __user *) addr; 190 191 if (addr == FETCH_TOKEN_COMM) 192 len = strlen(current->comm) + 1; 193 else 194 len = strnlen_user(vaddr, MAX_STRING_SIZE); 195 196 return (len > MAX_STRING_SIZE) ? 0 : len; 197 } 198 199 static nokprobe_inline int 200 fetch_store_strlen_user(unsigned long addr) 201 { 202 return fetch_store_strlen(addr); 203 } 204 205 static unsigned long translate_user_vaddr(unsigned long file_offset) 206 { 207 unsigned long base_addr; 208 struct uprobe_dispatch_data *udd; 209 210 udd = (void *) current->utask->vaddr; 211 212 base_addr = udd->bp_addr - udd->tu->offset; 213 return base_addr + file_offset; 214 } 215 216 /* Note that we don't verify it, since the code does not come from user space */ 217 static int 218 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 219 void *base) 220 { 221 struct pt_regs *regs = rec; 222 unsigned long val; 223 int ret; 224 225 /* 1st stage: get value from context */ 226 switch (code->op) { 227 case FETCH_OP_REG: 228 val = regs_get_register(regs, code->param); 229 break; 230 case FETCH_OP_STACK: 231 val = get_user_stack_nth(regs, code->param); 232 break; 233 case FETCH_OP_STACKP: 234 val = user_stack_pointer(regs); 235 break; 236 case FETCH_OP_RETVAL: 237 val = regs_return_value(regs); 238 break; 239 case FETCH_OP_COMM: 240 val = FETCH_TOKEN_COMM; 241 break; 242 case FETCH_OP_FOFFS: 243 val = translate_user_vaddr(code->immediate); 244 break; 245 default: 246 ret = process_common_fetch_insn(code, &val); 247 if (ret < 0) 248 return ret; 249 } 250 code++; 251 252 return process_fetch_insn_bottom(code, val, dest, base); 253 } 254 NOKPROBE_SYMBOL(process_fetch_insn) 255 256 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 257 { 258 rwlock_init(&filter->rwlock); 259 filter->nr_systemwide = 0; 260 INIT_LIST_HEAD(&filter->perf_events); 261 } 262 263 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 264 { 265 return !filter->nr_systemwide && list_empty(&filter->perf_events); 266 } 267 268 static inline bool is_ret_probe(struct trace_uprobe *tu) 269 { 270 return tu->consumer.ret_handler != NULL; 271 } 272 273 static bool trace_uprobe_is_busy(struct dyn_event *ev) 274 { 275 struct trace_uprobe *tu = to_trace_uprobe(ev); 276 277 return trace_probe_is_enabled(&tu->tp); 278 } 279 280 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 281 int argc, const char **argv) 282 { 283 char buf[MAX_ARGSTR_LEN + 1]; 284 int len; 285 286 if (!argc) 287 return true; 288 289 len = strlen(tu->filename); 290 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 291 return false; 292 293 if (tu->ref_ctr_offset == 0) 294 snprintf(buf, sizeof(buf), "0x%0*lx", 295 (int)(sizeof(void *) * 2), tu->offset); 296 else 297 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 298 (int)(sizeof(void *) * 2), tu->offset, 299 tu->ref_ctr_offset); 300 if (strcmp(buf, &argv[0][len + 1])) 301 return false; 302 303 argc--; argv++; 304 305 return trace_probe_match_command_args(&tu->tp, argc, argv); 306 } 307 308 static bool trace_uprobe_match(const char *system, const char *event, 309 int argc, const char **argv, struct dyn_event *ev) 310 { 311 struct trace_uprobe *tu = to_trace_uprobe(ev); 312 313 return (event[0] == '\0' || 314 strcmp(trace_probe_name(&tu->tp), event) == 0) && 315 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && 316 trace_uprobe_match_command_head(tu, argc, argv); 317 } 318 319 static nokprobe_inline struct trace_uprobe * 320 trace_uprobe_primary_from_call(struct trace_event_call *call) 321 { 322 struct trace_probe *tp; 323 324 tp = trace_probe_primary_from_call(call); 325 if (WARN_ON_ONCE(!tp)) 326 return NULL; 327 328 return container_of(tp, struct trace_uprobe, tp); 329 } 330 331 /* 332 * Allocate new trace_uprobe and initialize it (including uprobes). 333 */ 334 static struct trace_uprobe * 335 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) 336 { 337 struct trace_uprobe *tu; 338 int ret; 339 340 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); 341 if (!tu) 342 return ERR_PTR(-ENOMEM); 343 344 ret = trace_probe_init(&tu->tp, event, group, true); 345 if (ret < 0) 346 goto error; 347 348 dyn_event_init(&tu->devent, &trace_uprobe_ops); 349 tu->consumer.handler = uprobe_dispatcher; 350 if (is_ret) 351 tu->consumer.ret_handler = uretprobe_dispatcher; 352 init_trace_uprobe_filter(tu->tp.event->filter); 353 return tu; 354 355 error: 356 kfree(tu); 357 358 return ERR_PTR(ret); 359 } 360 361 static void free_trace_uprobe(struct trace_uprobe *tu) 362 { 363 if (!tu) 364 return; 365 366 path_put(&tu->path); 367 trace_probe_cleanup(&tu->tp); 368 kfree(tu->filename); 369 kfree(tu); 370 } 371 372 static struct trace_uprobe *find_probe_event(const char *event, const char *group) 373 { 374 struct dyn_event *pos; 375 struct trace_uprobe *tu; 376 377 for_each_trace_uprobe(tu, pos) 378 if (strcmp(trace_probe_name(&tu->tp), event) == 0 && 379 strcmp(trace_probe_group_name(&tu->tp), group) == 0) 380 return tu; 381 382 return NULL; 383 } 384 385 /* Unregister a trace_uprobe and probe_event */ 386 static int unregister_trace_uprobe(struct trace_uprobe *tu) 387 { 388 int ret; 389 390 if (trace_probe_has_sibling(&tu->tp)) 391 goto unreg; 392 393 /* If there's a reference to the dynamic event */ 394 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) 395 return -EBUSY; 396 397 ret = unregister_uprobe_event(tu); 398 if (ret) 399 return ret; 400 401 unreg: 402 dyn_event_remove(&tu->devent); 403 trace_probe_unlink(&tu->tp); 404 free_trace_uprobe(tu); 405 return 0; 406 } 407 408 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, 409 struct trace_uprobe *comp) 410 { 411 struct trace_probe_event *tpe = orig->tp.event; 412 struct inode *comp_inode = d_real_inode(comp->path.dentry); 413 int i; 414 415 list_for_each_entry(orig, &tpe->probes, tp.list) { 416 if (comp_inode != d_real_inode(orig->path.dentry) || 417 comp->offset != orig->offset) 418 continue; 419 420 /* 421 * trace_probe_compare_arg_type() ensured that nr_args and 422 * each argument name and type are same. Let's compare comm. 423 */ 424 for (i = 0; i < orig->tp.nr_args; i++) { 425 if (strcmp(orig->tp.args[i].comm, 426 comp->tp.args[i].comm)) 427 break; 428 } 429 430 if (i == orig->tp.nr_args) 431 return true; 432 } 433 434 return false; 435 } 436 437 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) 438 { 439 int ret; 440 441 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); 442 if (ret) { 443 /* Note that argument starts index = 2 */ 444 trace_probe_log_set_index(ret + 1); 445 trace_probe_log_err(0, DIFF_ARG_TYPE); 446 return -EEXIST; 447 } 448 if (trace_uprobe_has_same_uprobe(to, tu)) { 449 trace_probe_log_set_index(0); 450 trace_probe_log_err(0, SAME_PROBE); 451 return -EEXIST; 452 } 453 454 /* Append to existing event */ 455 ret = trace_probe_append(&tu->tp, &to->tp); 456 if (!ret) 457 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 458 459 return ret; 460 } 461 462 /* 463 * Uprobe with multiple reference counter is not allowed. i.e. 464 * If inode and offset matches, reference counter offset *must* 465 * match as well. Though, there is one exception: If user is 466 * replacing old trace_uprobe with new one(same group/event), 467 * then we allow same uprobe with new reference counter as far 468 * as the new one does not conflict with any other existing 469 * ones. 470 */ 471 static int validate_ref_ctr_offset(struct trace_uprobe *new) 472 { 473 struct dyn_event *pos; 474 struct trace_uprobe *tmp; 475 struct inode *new_inode = d_real_inode(new->path.dentry); 476 477 for_each_trace_uprobe(tmp, pos) { 478 if (new_inode == d_real_inode(tmp->path.dentry) && 479 new->offset == tmp->offset && 480 new->ref_ctr_offset != tmp->ref_ctr_offset) { 481 pr_warn("Reference counter offset mismatch."); 482 return -EINVAL; 483 } 484 } 485 return 0; 486 } 487 488 /* Register a trace_uprobe and probe_event */ 489 static int register_trace_uprobe(struct trace_uprobe *tu) 490 { 491 struct trace_uprobe *old_tu; 492 int ret; 493 494 mutex_lock(&event_mutex); 495 496 ret = validate_ref_ctr_offset(tu); 497 if (ret) 498 goto end; 499 500 /* register as an event */ 501 old_tu = find_probe_event(trace_probe_name(&tu->tp), 502 trace_probe_group_name(&tu->tp)); 503 if (old_tu) { 504 if (is_ret_probe(tu) != is_ret_probe(old_tu)) { 505 trace_probe_log_set_index(0); 506 trace_probe_log_err(0, DIFF_PROBE_TYPE); 507 ret = -EEXIST; 508 } else { 509 ret = append_trace_uprobe(tu, old_tu); 510 } 511 goto end; 512 } 513 514 ret = register_uprobe_event(tu); 515 if (ret) { 516 if (ret == -EEXIST) { 517 trace_probe_log_set_index(0); 518 trace_probe_log_err(0, EVENT_EXIST); 519 } else 520 pr_warn("Failed to register probe event(%d)\n", ret); 521 goto end; 522 } 523 524 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 525 526 end: 527 mutex_unlock(&event_mutex); 528 529 return ret; 530 } 531 532 /* 533 * Argument syntax: 534 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] 535 */ 536 static int __trace_uprobe_create(int argc, const char **argv) 537 { 538 struct trace_uprobe *tu; 539 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; 540 char *arg, *filename, *rctr, *rctr_end, *tmp; 541 char buf[MAX_EVENT_NAME_LEN]; 542 char gbuf[MAX_EVENT_NAME_LEN]; 543 enum probe_print_type ptype; 544 struct path path; 545 unsigned long offset, ref_ctr_offset; 546 bool is_return = false; 547 int i, ret; 548 549 ref_ctr_offset = 0; 550 551 switch (argv[0][0]) { 552 case 'r': 553 is_return = true; 554 break; 555 case 'p': 556 break; 557 default: 558 return -ECANCELED; 559 } 560 561 if (argc < 2) 562 return -ECANCELED; 563 564 if (argv[0][1] == ':') 565 event = &argv[0][2]; 566 567 if (!strchr(argv[1], '/')) 568 return -ECANCELED; 569 570 filename = kstrdup(argv[1], GFP_KERNEL); 571 if (!filename) 572 return -ENOMEM; 573 574 /* Find the last occurrence, in case the path contains ':' too. */ 575 arg = strrchr(filename, ':'); 576 if (!arg || !isdigit(arg[1])) { 577 kfree(filename); 578 return -ECANCELED; 579 } 580 581 trace_probe_log_init("trace_uprobe", argc, argv); 582 trace_probe_log_set_index(1); /* filename is the 2nd argument */ 583 584 *arg++ = '\0'; 585 ret = kern_path(filename, LOOKUP_FOLLOW, &path); 586 if (ret) { 587 trace_probe_log_err(0, FILE_NOT_FOUND); 588 kfree(filename); 589 trace_probe_log_clear(); 590 return ret; 591 } 592 if (!d_is_reg(path.dentry)) { 593 trace_probe_log_err(0, NO_REGULAR_FILE); 594 ret = -EINVAL; 595 goto fail_address_parse; 596 } 597 598 /* Parse reference counter offset if specified. */ 599 rctr = strchr(arg, '('); 600 if (rctr) { 601 rctr_end = strchr(rctr, ')'); 602 if (!rctr_end) { 603 ret = -EINVAL; 604 rctr_end = rctr + strlen(rctr); 605 trace_probe_log_err(rctr_end - filename, 606 REFCNT_OPEN_BRACE); 607 goto fail_address_parse; 608 } else if (rctr_end[1] != '\0') { 609 ret = -EINVAL; 610 trace_probe_log_err(rctr_end + 1 - filename, 611 BAD_REFCNT_SUFFIX); 612 goto fail_address_parse; 613 } 614 615 *rctr++ = '\0'; 616 *rctr_end = '\0'; 617 ret = kstrtoul(rctr, 0, &ref_ctr_offset); 618 if (ret) { 619 trace_probe_log_err(rctr - filename, BAD_REFCNT); 620 goto fail_address_parse; 621 } 622 } 623 624 /* Check if there is %return suffix */ 625 tmp = strchr(arg, '%'); 626 if (tmp) { 627 if (!strcmp(tmp, "%return")) { 628 *tmp = '\0'; 629 is_return = true; 630 } else { 631 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); 632 ret = -EINVAL; 633 goto fail_address_parse; 634 } 635 } 636 637 /* Parse uprobe offset. */ 638 ret = kstrtoul(arg, 0, &offset); 639 if (ret) { 640 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 641 goto fail_address_parse; 642 } 643 644 /* setup a probe */ 645 trace_probe_log_set_index(0); 646 if (event) { 647 ret = traceprobe_parse_event_name(&event, &group, gbuf, 648 event - argv[0]); 649 if (ret) 650 goto fail_address_parse; 651 } 652 653 if (!event) { 654 char *tail; 655 char *ptr; 656 657 tail = kstrdup(kbasename(filename), GFP_KERNEL); 658 if (!tail) { 659 ret = -ENOMEM; 660 goto fail_address_parse; 661 } 662 663 ptr = strpbrk(tail, ".-_"); 664 if (ptr) 665 *ptr = '\0'; 666 667 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 668 event = buf; 669 kfree(tail); 670 } 671 672 argc -= 2; 673 argv += 2; 674 675 tu = alloc_trace_uprobe(group, event, argc, is_return); 676 if (IS_ERR(tu)) { 677 ret = PTR_ERR(tu); 678 /* This must return -ENOMEM otherwise there is a bug */ 679 WARN_ON_ONCE(ret != -ENOMEM); 680 goto fail_address_parse; 681 } 682 tu->offset = offset; 683 tu->ref_ctr_offset = ref_ctr_offset; 684 tu->path = path; 685 tu->filename = filename; 686 687 /* parse arguments */ 688 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 689 struct traceprobe_parse_context ctx = { 690 .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER, 691 }; 692 693 trace_probe_log_set_index(i + 2); 694 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx); 695 if (ret) 696 goto error; 697 } 698 699 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 700 ret = traceprobe_set_print_fmt(&tu->tp, ptype); 701 if (ret < 0) 702 goto error; 703 704 ret = register_trace_uprobe(tu); 705 if (!ret) 706 goto out; 707 708 error: 709 free_trace_uprobe(tu); 710 out: 711 trace_probe_log_clear(); 712 return ret; 713 714 fail_address_parse: 715 trace_probe_log_clear(); 716 path_put(&path); 717 kfree(filename); 718 719 return ret; 720 } 721 722 int trace_uprobe_create(const char *raw_command) 723 { 724 return trace_probe_create(raw_command, __trace_uprobe_create); 725 } 726 727 static int create_or_delete_trace_uprobe(const char *raw_command) 728 { 729 int ret; 730 731 if (raw_command[0] == '-') 732 return dyn_event_release(raw_command, &trace_uprobe_ops); 733 734 ret = trace_uprobe_create(raw_command); 735 return ret == -ECANCELED ? -EINVAL : ret; 736 } 737 738 static int trace_uprobe_release(struct dyn_event *ev) 739 { 740 struct trace_uprobe *tu = to_trace_uprobe(ev); 741 742 return unregister_trace_uprobe(tu); 743 } 744 745 /* Probes listing interfaces */ 746 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 747 { 748 struct trace_uprobe *tu = to_trace_uprobe(ev); 749 char c = is_ret_probe(tu) ? 'r' : 'p'; 750 int i; 751 752 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 753 trace_probe_name(&tu->tp), tu->filename, 754 (int)(sizeof(void *) * 2), tu->offset); 755 756 if (tu->ref_ctr_offset) 757 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 758 759 for (i = 0; i < tu->tp.nr_args; i++) 760 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 761 762 seq_putc(m, '\n'); 763 return 0; 764 } 765 766 static int probes_seq_show(struct seq_file *m, void *v) 767 { 768 struct dyn_event *ev = v; 769 770 if (!is_trace_uprobe(ev)) 771 return 0; 772 773 return trace_uprobe_show(m, ev); 774 } 775 776 static const struct seq_operations probes_seq_op = { 777 .start = dyn_event_seq_start, 778 .next = dyn_event_seq_next, 779 .stop = dyn_event_seq_stop, 780 .show = probes_seq_show 781 }; 782 783 static int probes_open(struct inode *inode, struct file *file) 784 { 785 int ret; 786 787 ret = security_locked_down(LOCKDOWN_TRACEFS); 788 if (ret) 789 return ret; 790 791 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 792 ret = dyn_events_release_all(&trace_uprobe_ops); 793 if (ret) 794 return ret; 795 } 796 797 return seq_open(file, &probes_seq_op); 798 } 799 800 static ssize_t probes_write(struct file *file, const char __user *buffer, 801 size_t count, loff_t *ppos) 802 { 803 return trace_parse_run_command(file, buffer, count, ppos, 804 create_or_delete_trace_uprobe); 805 } 806 807 static const struct file_operations uprobe_events_ops = { 808 .owner = THIS_MODULE, 809 .open = probes_open, 810 .read = seq_read, 811 .llseek = seq_lseek, 812 .release = seq_release, 813 .write = probes_write, 814 }; 815 816 /* Probes profiling interfaces */ 817 static int probes_profile_seq_show(struct seq_file *m, void *v) 818 { 819 struct dyn_event *ev = v; 820 struct trace_uprobe *tu; 821 822 if (!is_trace_uprobe(ev)) 823 return 0; 824 825 tu = to_trace_uprobe(ev); 826 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 827 trace_probe_name(&tu->tp), tu->nhit); 828 return 0; 829 } 830 831 static const struct seq_operations profile_seq_op = { 832 .start = dyn_event_seq_start, 833 .next = dyn_event_seq_next, 834 .stop = dyn_event_seq_stop, 835 .show = probes_profile_seq_show 836 }; 837 838 static int profile_open(struct inode *inode, struct file *file) 839 { 840 int ret; 841 842 ret = security_locked_down(LOCKDOWN_TRACEFS); 843 if (ret) 844 return ret; 845 846 return seq_open(file, &profile_seq_op); 847 } 848 849 static const struct file_operations uprobe_profile_ops = { 850 .owner = THIS_MODULE, 851 .open = profile_open, 852 .read = seq_read, 853 .llseek = seq_lseek, 854 .release = seq_release, 855 }; 856 857 struct uprobe_cpu_buffer { 858 struct mutex mutex; 859 void *buf; 860 }; 861 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 862 static int uprobe_buffer_refcnt; 863 864 static int uprobe_buffer_init(void) 865 { 866 int cpu, err_cpu; 867 868 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 869 if (uprobe_cpu_buffer == NULL) 870 return -ENOMEM; 871 872 for_each_possible_cpu(cpu) { 873 struct page *p = alloc_pages_node(cpu_to_node(cpu), 874 GFP_KERNEL, 0); 875 if (p == NULL) { 876 err_cpu = cpu; 877 goto err; 878 } 879 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 880 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 881 } 882 883 return 0; 884 885 err: 886 for_each_possible_cpu(cpu) { 887 if (cpu == err_cpu) 888 break; 889 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 890 } 891 892 free_percpu(uprobe_cpu_buffer); 893 return -ENOMEM; 894 } 895 896 static int uprobe_buffer_enable(void) 897 { 898 int ret = 0; 899 900 BUG_ON(!mutex_is_locked(&event_mutex)); 901 902 if (uprobe_buffer_refcnt++ == 0) { 903 ret = uprobe_buffer_init(); 904 if (ret < 0) 905 uprobe_buffer_refcnt--; 906 } 907 908 return ret; 909 } 910 911 static void uprobe_buffer_disable(void) 912 { 913 int cpu; 914 915 BUG_ON(!mutex_is_locked(&event_mutex)); 916 917 if (--uprobe_buffer_refcnt == 0) { 918 for_each_possible_cpu(cpu) 919 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 920 cpu)->buf); 921 922 free_percpu(uprobe_cpu_buffer); 923 uprobe_cpu_buffer = NULL; 924 } 925 } 926 927 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 928 { 929 struct uprobe_cpu_buffer *ucb; 930 int cpu; 931 932 cpu = raw_smp_processor_id(); 933 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 934 935 /* 936 * Use per-cpu buffers for fastest access, but we might migrate 937 * so the mutex makes sure we have sole access to it. 938 */ 939 mutex_lock(&ucb->mutex); 940 941 return ucb; 942 } 943 944 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 945 { 946 mutex_unlock(&ucb->mutex); 947 } 948 949 static void __uprobe_trace_func(struct trace_uprobe *tu, 950 unsigned long func, struct pt_regs *regs, 951 struct uprobe_cpu_buffer *ucb, int dsize, 952 struct trace_event_file *trace_file) 953 { 954 struct uprobe_trace_entry_head *entry; 955 struct trace_event_buffer fbuffer; 956 void *data; 957 int size, esize; 958 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 959 960 WARN_ON(call != trace_file->event_call); 961 962 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 963 return; 964 965 if (trace_trigger_soft_disabled(trace_file)) 966 return; 967 968 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 969 size = esize + tu->tp.size + dsize; 970 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 971 if (!entry) 972 return; 973 974 if (is_ret_probe(tu)) { 975 entry->vaddr[0] = func; 976 entry->vaddr[1] = instruction_pointer(regs); 977 data = DATAOF_TRACE_ENTRY(entry, true); 978 } else { 979 entry->vaddr[0] = instruction_pointer(regs); 980 data = DATAOF_TRACE_ENTRY(entry, false); 981 } 982 983 memcpy(data, ucb->buf, tu->tp.size + dsize); 984 985 trace_event_buffer_commit(&fbuffer); 986 } 987 988 /* uprobe handler */ 989 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 990 struct uprobe_cpu_buffer *ucb, int dsize) 991 { 992 struct event_file_link *link; 993 994 if (is_ret_probe(tu)) 995 return 0; 996 997 rcu_read_lock(); 998 trace_probe_for_each_link_rcu(link, &tu->tp) 999 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 1000 rcu_read_unlock(); 1001 1002 return 0; 1003 } 1004 1005 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1006 struct pt_regs *regs, 1007 struct uprobe_cpu_buffer *ucb, int dsize) 1008 { 1009 struct event_file_link *link; 1010 1011 rcu_read_lock(); 1012 trace_probe_for_each_link_rcu(link, &tu->tp) 1013 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 1014 rcu_read_unlock(); 1015 } 1016 1017 /* Event entry printers */ 1018 static enum print_line_t 1019 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1020 { 1021 struct uprobe_trace_entry_head *entry; 1022 struct trace_seq *s = &iter->seq; 1023 struct trace_uprobe *tu; 1024 u8 *data; 1025 1026 entry = (struct uprobe_trace_entry_head *)iter->ent; 1027 tu = trace_uprobe_primary_from_call( 1028 container_of(event, struct trace_event_call, event)); 1029 if (unlikely(!tu)) 1030 goto out; 1031 1032 if (is_ret_probe(tu)) { 1033 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1034 trace_probe_name(&tu->tp), 1035 entry->vaddr[1], entry->vaddr[0]); 1036 data = DATAOF_TRACE_ENTRY(entry, true); 1037 } else { 1038 trace_seq_printf(s, "%s: (0x%lx)", 1039 trace_probe_name(&tu->tp), 1040 entry->vaddr[0]); 1041 data = DATAOF_TRACE_ENTRY(entry, false); 1042 } 1043 1044 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1045 goto out; 1046 1047 trace_seq_putc(s, '\n'); 1048 1049 out: 1050 return trace_handle_return(s); 1051 } 1052 1053 typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1054 enum uprobe_filter_ctx ctx, 1055 struct mm_struct *mm); 1056 1057 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1058 { 1059 int ret; 1060 1061 tu->consumer.filter = filter; 1062 tu->inode = d_real_inode(tu->path.dentry); 1063 1064 if (tu->ref_ctr_offset) 1065 ret = uprobe_register_refctr(tu->inode, tu->offset, 1066 tu->ref_ctr_offset, &tu->consumer); 1067 else 1068 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1069 1070 if (ret) 1071 tu->inode = NULL; 1072 1073 return ret; 1074 } 1075 1076 static void __probe_event_disable(struct trace_probe *tp) 1077 { 1078 struct trace_uprobe *tu; 1079 1080 tu = container_of(tp, struct trace_uprobe, tp); 1081 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1082 1083 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1084 if (!tu->inode) 1085 continue; 1086 1087 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1088 tu->inode = NULL; 1089 } 1090 } 1091 1092 static int probe_event_enable(struct trace_event_call *call, 1093 struct trace_event_file *file, filter_func_t filter) 1094 { 1095 struct trace_probe *tp; 1096 struct trace_uprobe *tu; 1097 bool enabled; 1098 int ret; 1099 1100 tp = trace_probe_primary_from_call(call); 1101 if (WARN_ON_ONCE(!tp)) 1102 return -ENODEV; 1103 enabled = trace_probe_is_enabled(tp); 1104 1105 /* This may also change "enabled" state */ 1106 if (file) { 1107 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1108 return -EINTR; 1109 1110 ret = trace_probe_add_file(tp, file); 1111 if (ret < 0) 1112 return ret; 1113 } else { 1114 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1115 return -EINTR; 1116 1117 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1118 } 1119 1120 tu = container_of(tp, struct trace_uprobe, tp); 1121 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1122 1123 if (enabled) 1124 return 0; 1125 1126 ret = uprobe_buffer_enable(); 1127 if (ret) 1128 goto err_flags; 1129 1130 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1131 ret = trace_uprobe_enable(tu, filter); 1132 if (ret) { 1133 __probe_event_disable(tp); 1134 goto err_buffer; 1135 } 1136 } 1137 1138 return 0; 1139 1140 err_buffer: 1141 uprobe_buffer_disable(); 1142 1143 err_flags: 1144 if (file) 1145 trace_probe_remove_file(tp, file); 1146 else 1147 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1148 1149 return ret; 1150 } 1151 1152 static void probe_event_disable(struct trace_event_call *call, 1153 struct trace_event_file *file) 1154 { 1155 struct trace_probe *tp; 1156 1157 tp = trace_probe_primary_from_call(call); 1158 if (WARN_ON_ONCE(!tp)) 1159 return; 1160 1161 if (!trace_probe_is_enabled(tp)) 1162 return; 1163 1164 if (file) { 1165 if (trace_probe_remove_file(tp, file) < 0) 1166 return; 1167 1168 if (trace_probe_is_enabled(tp)) 1169 return; 1170 } else 1171 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1172 1173 __probe_event_disable(tp); 1174 uprobe_buffer_disable(); 1175 } 1176 1177 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1178 { 1179 int ret, size; 1180 struct uprobe_trace_entry_head field; 1181 struct trace_uprobe *tu; 1182 1183 tu = trace_uprobe_primary_from_call(event_call); 1184 if (unlikely(!tu)) 1185 return -ENODEV; 1186 1187 if (is_ret_probe(tu)) { 1188 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1189 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1190 size = SIZEOF_TRACE_ENTRY(true); 1191 } else { 1192 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1193 size = SIZEOF_TRACE_ENTRY(false); 1194 } 1195 1196 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1197 } 1198 1199 #ifdef CONFIG_PERF_EVENTS 1200 static bool 1201 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1202 { 1203 struct perf_event *event; 1204 1205 if (filter->nr_systemwide) 1206 return true; 1207 1208 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1209 if (event->hw.target->mm == mm) 1210 return true; 1211 } 1212 1213 return false; 1214 } 1215 1216 static inline bool 1217 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1218 struct perf_event *event) 1219 { 1220 return __uprobe_perf_filter(filter, event->hw.target->mm); 1221 } 1222 1223 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1224 struct perf_event *event) 1225 { 1226 bool done; 1227 1228 write_lock(&filter->rwlock); 1229 if (event->hw.target) { 1230 list_del(&event->hw.tp_list); 1231 done = filter->nr_systemwide || 1232 (event->hw.target->flags & PF_EXITING) || 1233 trace_uprobe_filter_event(filter, event); 1234 } else { 1235 filter->nr_systemwide--; 1236 done = filter->nr_systemwide; 1237 } 1238 write_unlock(&filter->rwlock); 1239 1240 return done; 1241 } 1242 1243 /* This returns true if the filter always covers target mm */ 1244 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1245 struct perf_event *event) 1246 { 1247 bool done; 1248 1249 write_lock(&filter->rwlock); 1250 if (event->hw.target) { 1251 /* 1252 * event->parent != NULL means copy_process(), we can avoid 1253 * uprobe_apply(). current->mm must be probed and we can rely 1254 * on dup_mmap() which preserves the already installed bp's. 1255 * 1256 * attr.enable_on_exec means that exec/mmap will install the 1257 * breakpoints we need. 1258 */ 1259 done = filter->nr_systemwide || 1260 event->parent || event->attr.enable_on_exec || 1261 trace_uprobe_filter_event(filter, event); 1262 list_add(&event->hw.tp_list, &filter->perf_events); 1263 } else { 1264 done = filter->nr_systemwide; 1265 filter->nr_systemwide++; 1266 } 1267 write_unlock(&filter->rwlock); 1268 1269 return done; 1270 } 1271 1272 static int uprobe_perf_close(struct trace_event_call *call, 1273 struct perf_event *event) 1274 { 1275 struct trace_probe *tp; 1276 struct trace_uprobe *tu; 1277 int ret = 0; 1278 1279 tp = trace_probe_primary_from_call(call); 1280 if (WARN_ON_ONCE(!tp)) 1281 return -ENODEV; 1282 1283 tu = container_of(tp, struct trace_uprobe, tp); 1284 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1285 return 0; 1286 1287 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1288 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1289 if (ret) 1290 break; 1291 } 1292 1293 return ret; 1294 } 1295 1296 static int uprobe_perf_open(struct trace_event_call *call, 1297 struct perf_event *event) 1298 { 1299 struct trace_probe *tp; 1300 struct trace_uprobe *tu; 1301 int err = 0; 1302 1303 tp = trace_probe_primary_from_call(call); 1304 if (WARN_ON_ONCE(!tp)) 1305 return -ENODEV; 1306 1307 tu = container_of(tp, struct trace_uprobe, tp); 1308 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1309 return 0; 1310 1311 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1312 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1313 if (err) { 1314 uprobe_perf_close(call, event); 1315 break; 1316 } 1317 } 1318 1319 return err; 1320 } 1321 1322 static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1323 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1324 { 1325 struct trace_uprobe_filter *filter; 1326 struct trace_uprobe *tu; 1327 int ret; 1328 1329 tu = container_of(uc, struct trace_uprobe, consumer); 1330 filter = tu->tp.event->filter; 1331 1332 read_lock(&filter->rwlock); 1333 ret = __uprobe_perf_filter(filter, mm); 1334 read_unlock(&filter->rwlock); 1335 1336 return ret; 1337 } 1338 1339 static void __uprobe_perf_func(struct trace_uprobe *tu, 1340 unsigned long func, struct pt_regs *regs, 1341 struct uprobe_cpu_buffer *ucb, int dsize) 1342 { 1343 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1344 struct uprobe_trace_entry_head *entry; 1345 struct hlist_head *head; 1346 void *data; 1347 int size, esize; 1348 int rctx; 1349 1350 #ifdef CONFIG_BPF_EVENTS 1351 if (bpf_prog_array_valid(call)) { 1352 u32 ret; 1353 1354 ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run); 1355 if (!ret) 1356 return; 1357 } 1358 #endif /* CONFIG_BPF_EVENTS */ 1359 1360 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1361 1362 size = esize + tu->tp.size + dsize; 1363 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1364 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1365 return; 1366 1367 preempt_disable(); 1368 head = this_cpu_ptr(call->perf_events); 1369 if (hlist_empty(head)) 1370 goto out; 1371 1372 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1373 if (!entry) 1374 goto out; 1375 1376 if (is_ret_probe(tu)) { 1377 entry->vaddr[0] = func; 1378 entry->vaddr[1] = instruction_pointer(regs); 1379 data = DATAOF_TRACE_ENTRY(entry, true); 1380 } else { 1381 entry->vaddr[0] = instruction_pointer(regs); 1382 data = DATAOF_TRACE_ENTRY(entry, false); 1383 } 1384 1385 memcpy(data, ucb->buf, tu->tp.size + dsize); 1386 1387 if (size - esize > tu->tp.size + dsize) { 1388 int len = tu->tp.size + dsize; 1389 1390 memset(data + len, 0, size - esize - len); 1391 } 1392 1393 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1394 head, NULL); 1395 out: 1396 preempt_enable(); 1397 } 1398 1399 /* uprobe profile handler */ 1400 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1401 struct uprobe_cpu_buffer *ucb, int dsize) 1402 { 1403 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1404 return UPROBE_HANDLER_REMOVE; 1405 1406 if (!is_ret_probe(tu)) 1407 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1408 return 0; 1409 } 1410 1411 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1412 struct pt_regs *regs, 1413 struct uprobe_cpu_buffer *ucb, int dsize) 1414 { 1415 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1416 } 1417 1418 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1419 const char **filename, u64 *probe_offset, 1420 bool perf_type_tracepoint) 1421 { 1422 const char *pevent = trace_event_name(event->tp_event); 1423 const char *group = event->tp_event->class->system; 1424 struct trace_uprobe *tu; 1425 1426 if (perf_type_tracepoint) 1427 tu = find_probe_event(pevent, group); 1428 else 1429 tu = trace_uprobe_primary_from_call(event->tp_event); 1430 if (!tu) 1431 return -EINVAL; 1432 1433 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1434 : BPF_FD_TYPE_UPROBE; 1435 *filename = tu->filename; 1436 *probe_offset = tu->offset; 1437 return 0; 1438 } 1439 #endif /* CONFIG_PERF_EVENTS */ 1440 1441 static int 1442 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1443 void *data) 1444 { 1445 struct trace_event_file *file = data; 1446 1447 switch (type) { 1448 case TRACE_REG_REGISTER: 1449 return probe_event_enable(event, file, NULL); 1450 1451 case TRACE_REG_UNREGISTER: 1452 probe_event_disable(event, file); 1453 return 0; 1454 1455 #ifdef CONFIG_PERF_EVENTS 1456 case TRACE_REG_PERF_REGISTER: 1457 return probe_event_enable(event, NULL, uprobe_perf_filter); 1458 1459 case TRACE_REG_PERF_UNREGISTER: 1460 probe_event_disable(event, NULL); 1461 return 0; 1462 1463 case TRACE_REG_PERF_OPEN: 1464 return uprobe_perf_open(event, data); 1465 1466 case TRACE_REG_PERF_CLOSE: 1467 return uprobe_perf_close(event, data); 1468 1469 #endif 1470 default: 1471 return 0; 1472 } 1473 } 1474 1475 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1476 { 1477 struct trace_uprobe *tu; 1478 struct uprobe_dispatch_data udd; 1479 struct uprobe_cpu_buffer *ucb; 1480 int dsize, esize; 1481 int ret = 0; 1482 1483 1484 tu = container_of(con, struct trace_uprobe, consumer); 1485 tu->nhit++; 1486 1487 udd.tu = tu; 1488 udd.bp_addr = instruction_pointer(regs); 1489 1490 current->utask->vaddr = (unsigned long) &udd; 1491 1492 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1493 return 0; 1494 1495 dsize = __get_data_size(&tu->tp, regs); 1496 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1497 1498 ucb = uprobe_buffer_get(); 1499 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1500 1501 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1502 ret |= uprobe_trace_func(tu, regs, ucb, dsize); 1503 1504 #ifdef CONFIG_PERF_EVENTS 1505 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1506 ret |= uprobe_perf_func(tu, regs, ucb, dsize); 1507 #endif 1508 uprobe_buffer_put(ucb); 1509 return ret; 1510 } 1511 1512 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1513 unsigned long func, struct pt_regs *regs) 1514 { 1515 struct trace_uprobe *tu; 1516 struct uprobe_dispatch_data udd; 1517 struct uprobe_cpu_buffer *ucb; 1518 int dsize, esize; 1519 1520 tu = container_of(con, struct trace_uprobe, consumer); 1521 1522 udd.tu = tu; 1523 udd.bp_addr = func; 1524 1525 current->utask->vaddr = (unsigned long) &udd; 1526 1527 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1528 return 0; 1529 1530 dsize = __get_data_size(&tu->tp, regs); 1531 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1532 1533 ucb = uprobe_buffer_get(); 1534 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1535 1536 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1537 uretprobe_trace_func(tu, func, regs, ucb, dsize); 1538 1539 #ifdef CONFIG_PERF_EVENTS 1540 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1541 uretprobe_perf_func(tu, func, regs, ucb, dsize); 1542 #endif 1543 uprobe_buffer_put(ucb); 1544 return 0; 1545 } 1546 1547 static struct trace_event_functions uprobe_funcs = { 1548 .trace = print_uprobe_event 1549 }; 1550 1551 static struct trace_event_fields uprobe_fields_array[] = { 1552 { .type = TRACE_FUNCTION_TYPE, 1553 .define_fields = uprobe_event_define_fields }, 1554 {} 1555 }; 1556 1557 static inline void init_trace_event_call(struct trace_uprobe *tu) 1558 { 1559 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1560 call->event.funcs = &uprobe_funcs; 1561 call->class->fields_array = uprobe_fields_array; 1562 1563 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1564 call->class->reg = trace_uprobe_register; 1565 } 1566 1567 static int register_uprobe_event(struct trace_uprobe *tu) 1568 { 1569 init_trace_event_call(tu); 1570 1571 return trace_probe_register_event_call(&tu->tp); 1572 } 1573 1574 static int unregister_uprobe_event(struct trace_uprobe *tu) 1575 { 1576 return trace_probe_unregister_event_call(&tu->tp); 1577 } 1578 1579 #ifdef CONFIG_PERF_EVENTS 1580 struct trace_event_call * 1581 create_local_trace_uprobe(char *name, unsigned long offs, 1582 unsigned long ref_ctr_offset, bool is_return) 1583 { 1584 enum probe_print_type ptype; 1585 struct trace_uprobe *tu; 1586 struct path path; 1587 int ret; 1588 1589 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1590 if (ret) 1591 return ERR_PTR(ret); 1592 1593 if (!d_is_reg(path.dentry)) { 1594 path_put(&path); 1595 return ERR_PTR(-EINVAL); 1596 } 1597 1598 /* 1599 * local trace_kprobes are not added to dyn_event, so they are never 1600 * searched in find_trace_kprobe(). Therefore, there is no concern of 1601 * duplicated name "DUMMY_EVENT" here. 1602 */ 1603 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1604 is_return); 1605 1606 if (IS_ERR(tu)) { 1607 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1608 (int)PTR_ERR(tu)); 1609 path_put(&path); 1610 return ERR_CAST(tu); 1611 } 1612 1613 tu->offset = offs; 1614 tu->path = path; 1615 tu->ref_ctr_offset = ref_ctr_offset; 1616 tu->filename = kstrdup(name, GFP_KERNEL); 1617 if (!tu->filename) { 1618 ret = -ENOMEM; 1619 goto error; 1620 } 1621 1622 init_trace_event_call(tu); 1623 1624 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1625 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { 1626 ret = -ENOMEM; 1627 goto error; 1628 } 1629 1630 return trace_probe_event_call(&tu->tp); 1631 error: 1632 free_trace_uprobe(tu); 1633 return ERR_PTR(ret); 1634 } 1635 1636 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1637 { 1638 struct trace_uprobe *tu; 1639 1640 tu = trace_uprobe_primary_from_call(event_call); 1641 1642 free_trace_uprobe(tu); 1643 } 1644 #endif /* CONFIG_PERF_EVENTS */ 1645 1646 /* Make a trace interface for controlling probe points */ 1647 static __init int init_uprobe_trace(void) 1648 { 1649 int ret; 1650 1651 ret = dyn_event_register(&trace_uprobe_ops); 1652 if (ret) 1653 return ret; 1654 1655 ret = tracing_init_dentry(); 1656 if (ret) 1657 return 0; 1658 1659 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL, 1660 NULL, &uprobe_events_ops); 1661 /* Profile interface */ 1662 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL, 1663 NULL, &uprobe_profile_ops); 1664 return 0; 1665 } 1666 1667 fs_initcall(init_uprobe_trace); 1668